rackham



Jan. l5, 1924.

G. J. RACKHAM ENDLESS TRACK VEHICLE 4 Shets-Sheet 1 Filed Jan. 16, 192:5A

lz 12 z3 2529 21 .Q 25 um 22 -ujenr Jan. l5, 1924.

G. J. RACKHAM ENDLESS TRACK VEHICLE Filed Jan. 15, 1923 4 Sheets-Shg et\2 U ,wenlr A D?, ZUM

Jan. 15, 1924. 1,480,692

G. J. RACKHAM Y ENDLESS TRAQK VEHICLE Filed Jan. 16

1925 4 Sheets-Sheet f5 Jan. l5, 1924.

G. J. RACKHAM ENDLESS TRACK VEHICLE:

Filed Jan. 15 1923 4 Sheets-Sheet 4 Patented 335.115, i924.

UNiTEDeiATEs GEORGE. DEN RACKHAM, 0F CHCAGO, ILLINOIS, ASSIGNR TO RGADLESS PATENT-S PATENT ermee.

'HO'LiTilNG COMANY, OI WASHINGTON, DISTRICT 0F COLUMBIA.

ENDLESS-TRACK VEHILE L Application led January 1S, i923. Serial No'. 613,004.

Vehicles, ol` which the following is a spicci-r fication.. A. i Y This invention relates tovehicles Aof the clase in which endlese tracks or tractor belts are employed vto sustain the vehicle Vand tra verse the ground und' particularly to that clase of such vehicles known iis fpiletlfiallr track machines" or those in which the front or slteering wheels of thtlireliiclere of the ordinary kind wliileihf'er fortiori of; the` vehicle in su'pported tineke or tractor belts. 1

Theobjcct of this VinventiflmitiQto-en construct the endlose track mechanism that it.,

may perform its functions with the greatest possible ease nndwithout undue strain on. the

mechanism or ahnormalsh'ocks tothe vehicle. In carrying out ni invention l provide ,n cliais'of anyF suite, )le kind and I support .the front end of 'the omissis in any suitable Y wav, either -by front vsteering` wheelsv of ordinary construction suchl ae are commonly used in half track machines, or lmay use endless track mechanism :it bolli ends of the cliassis,er the entire chassis iniiy be siip` ported on the' tractor mechanism. For coni V The chassis has,

vamience of illustration and description it may beassumed that -tliefront end of Ihe chassis is' supported iii any suitable way. the

i'ezir portion. however, being supported hy in v improved tractor mechanism.

Eiwitally connected to its' rear portion at eac side a-siib-framc which is mounted to rock about a horizontal. axis preferably situated 'midway between its front and rear ends. lliicli of the snl'i-fraiiicel Supports at its front vnd a pulley over'vi'liicli iin endless tractor lielt of Siiitahle construclion passes and by which the front portion of the helfis Supported. Another tractor supporting pulley 'on each side of the -vehicle is fixed to a rea'r shaft or axle mounted in bearings carricd'liy the chassis and powerfrom iaV the motor is applied to said rear axle. Thus Awhile the front portion of the traclror belt may rise and fall relatively to the chassis,

' the reac'iipoi'tionthereof has afxed relation thereto and the fixed :ixle always niuintaine :i fixed relation with the driving;r mechanism. l

The weight of the vehicle is transmitted to the lower runs of the trac-tor belts through body Supporting devices of novel construction carried by the subfi'ames. These iivi'ces are of 'such construction and are so v,connected 1ifi/ith the subgframesand with tls" Vvehicle body that they may move vertically to a. limited extent relativel to the chassis, may have asl-mrt fore anda -rocking movement in the sub-frames, und also a shortlateral or trIlSYQrBo movement in Said frames.'

.In thisffwa the, mechanism ki1iitoi'natically ,mxioiiimodat'=itself. to 'varying ,conditions und circumistitiiicel Tand assures Vthis"gieaiieet, ease of operation and freedom fromislioelfs and Strains.

The accompany-ing drawings show the'preierred way of emliodyingir my invention. in machines of the kind lieioife mentioned, Figure l is a side elevation of' the tractor mechanism at the rear end 'of the vehicle chassis.

Figure 2 is a )ian vienj of this mechanism on liotli sides oi the chassis, the top run -of the lui-actor heiten one eide of the vehiclebeing omitted in order to show certain mechanism which would otherwise lie hidden.`

The remaining Iigures are on an. enlarged scale. i

Figure 3 is a. detail view in section en the line 3--3 of Figureh'showing particu larly parts of one ol. the bod \r supqiortimggv devices sind the means empio ed for permitting laici-ai movement thereo.y

.Figure 4 is a detail view in section of one of the track wheels forming' part of the body supporting devices and illustrates thc` manner in which it is mounted and howI it engages the track.

Figure 5 is n side elevation of one of the sub-f1fames with parts of certain brackete carried thereby.

Figure (i is a View inside elevation showing particularly the.construction and manner of mounting one of :the bodygsupporting devices. j Y Figure 7A ige. a detail 4@in 4section on the line 7i7 `of Figure .f2 and shows 'rticularlyeipartof the adjustable` flexible suspension members on which the body rests.' l

.ien

Figure 8 is a. View of another part lot the suspending member Shown in Figure 7.

Fi ire 9'is a detail view in section on the line 9-9 of Figure 1 showing the reF lation of one of the driving pulleys with the tractor belt. 0

The chassis of the vehicle as shown is in the form of a frame 1 which comprises longitudinal side members connected by transverse members disposed at suitable intervals. Brackets 2 bolted to the chassis support a shaft 3 from which is suspended on each side of the vehiclea sub-frame which is mounted to swing or turn about the axis of said shaft. Each of these sub-frames comprises two Side plates 5 connected t0 a top plate 7 and spaced by intervening plates 6. Angle irons 8 are secured to the top plate and the side plates to strengthen the frame as shown in Figure 3. Each frame is open' at the bottom and the top plate extends over a portion only of the frame. thus leaving open Vspaces at the ends ofthe frame to accommodate parts of the tractor pulleys in the manner shown.A

The connection between each sub-frame and the shaft 3 is made by means of a bracket 9 bolted to the sub-frame and pivotally connected with the axle. The bra/ckets 9 as shown in Figure 2 are disposed in vertical planes beyond or on opposite sides of the brackets 2 and the shaft 3 is prolonged beyond the brackets 2 to engage the brackets 9.

In operation the front end of the tractor mechanism tends to rise and in order to preserve a proper normal position of the sub-frnmes relatively to the chassis I provide on each side of the vehicle springs 12 and 13 surrounding a rod 1() secured to the associated sub-frame and extendingthrough a bracket 11 projecting laterally -from Vthe chassis. The springs 13 are interposed between the sub-frames and the brackets 11 and while yielding to permit the front ends of the tractor belts to rise when encountering obstructions serve to ordinarily hold .the frames in normal position.

The front portion of each tractor belt engages a pulley 15 mounted in bearings in brackets 14 carried by the front end of the associated .sub-frame.v These brackets are slotted as indicated at 16 and are provided with adjusting devices 17 by means of which the position of the pulleys may be changed to vary the tension of thev belts in well known ways.

It will be observed that each front pulley 15 is mounted on a sub-frame which rocks side members of the chassis. Power is applied to the axle 19 in any suitable way as indicated at P in Figure 2.

Each tractor belt 21 may be of any usual or suitable construction so far as my present invention is concerned. The belts shown` each consists of shocs22 connected by links 23 in such. manner as to permit such freedom of movement that the tracks may be bent when passing the pulleys and may he also bent laterally to accommodate certain conditions. These links 23 may be' tubular as indicated in Figure 9. and they arepreferablyr of the general kind shown in my Patent o. 1.434.630 of Nov. 7, 1922 and also in my Patent 1.440.243 of December 26. 1922. The rear or driving ulleys 20 are y'ireferably sprocket pulleys, being provided with teeth which engage lugs 24 on the shoes 22 as indicated in Figure 9. In this way the vehicle is supported on the lower runs ol the belts. Provision is made for a vertical movementof each body supportinpr device in the sub-frame and for a transverse or lateral movement therein.

`More specifically, each body supporting.r device comprises wheels 49 mounted in parallel inverted Ushape frame members 42 connected by `rross bars 43. Each wheel is mounted in suitable bearings in the lower ends of the arms of a frame as shown in Fieuic 4.

The f-rames 42 are arranged between the side plates 5 of the sub-frames and the bop of each sub-frame is equipped with brackets 25 having central openings through which -extend guide sleeves 28 `which are fixed to'said brackets and extend a considerable distance above them. and also extend downwardly into the frames 42. These sleeves serve as guides for the vertical posts 29 which have endwise movement in the sleeves.

- The posts 29 are recessed on their lower ends and rest' on thrust bearings 30 in post supports 31. The posts are connected with the post supports by pins 32 extending from the supports into annular grooves in the posts.

The post supports 31 are suspended from the frames 42 b v hangers 50 which are pivotally connected to the frames 42 hv pins 45 extendingr through lues 44 of said frames and through the upper portions of the hangers. The hanger bearings may be lubricated in theI manner indicated at 52 and the pins 45 may be keyed to the frame as indicated at 46.

At their lower ends the hangers extend. under :ums of the post supports and are connecicfl thereto by balls 37 nn the ends of plugs 3T fitted in the post supports. At its upper cud nach post 29 is slotted at 33. The -lcvve 29 i2 L'iruilarly sloted at 36 and in the slotted portion of each post and. Sleeve is l meow mounted a pulley 35 pivoted at 34 to the post. Bythisconstruction the post and its' pulley may movevertically to a limited extent 1n the associated sleeve. In this way the body supporting devices may move vortically'in the sub-frames and are properly guided when so doing. The lower parts of,

. -frames 43 which carry the wheels 49 so that when the track belts are moved laterally the wheels 19 move with. them. The upper: Y tions of the frames 42 ma also rock ore and aft in the'sub-frames a ut the halla'nd socket -joints 37 thus giving a rocking movement to the wheels 49.

The manner in which the shifted sidewise is indicated callv in Figure 3.

he body supporting devices. therefore, have a fore and aft movement with the subframes when they swing onthe shaft 3 a vertical movement in the sleeves 28, an a. rocking and sidewise movement on theV bali and socket` joints 37. The shoes of the tractor belts may turn abo-.t the axes of the links 23 inthe manner indicated at A in Figure 3, this j ivotal movement being limited by 4 on the lower ends of the side plates 5.` n

iagrammati- It will be Observed oscene ming.- that in the special construction illustrated the hangers are inclined from top tob0t-' E l founded on -anfapplicat'ion for 'patent l iw L tcm downwardly in opposite direction so that when the frames 43 are swung laterally they are also given an angularl orL tilting. movement, indicated by the daehf-lnes in 'y Fig. 3, which results the wheels 49.

The-shaft 3 carried by thechassis is. e uipped on each side with 'a pulley 56 w ich rests on a rope, cable or chainv 54 mounted on the sub-frame. The rear end ofthe chain is connected to a bracket 53 on top of the sub-frame and the chain after assin across the ulleys 35 of the posts 59 an under the pu ey 56 of the shaft 3 is attached to an arm 60 associated with a cam in tilting the axes ,of

l 51) on a short shaft v'vmounted in a bracket 58 on the sub-frame'. The chain may provided with' a turn-buckle 55 for adjgustmg its length; The arm 60 is connected with a Y short length of chain 62 af'tached to a horizontally arranged'rod 64 supporting a cupl against which 'bears one endgof a stout coiled spring 71, the opposite eriiv of which rests against a supporting bracket .58 on the sub-frame. The rearl lcrtion of the rod 64 is lguided-by-a bracke and by means of the nuts 72, and 73 the tension of the s ring 71 may be adjusted tofcorrcs ond wit the weight or iced carried) and to' old the chain is 45. mi`

54 in normal position. The front end of the rod 64 carries a cu 66 into which extends the-rear end of a re ativcly small spring G7. ,the front end of which extends 'into the cup of the bracket 58. Screws 68,'69 hold the .sprin v A67 in place between the cups 66 and I0. '`he rod 64 carries adjustable nuts or stois 74, 75. The sprinig 71 is under tension an the 'spring 67 is put under tension only when the chain 54 is put under unusual'tew sin and pulls on the rod to an abnormally increased extent. Normally when the chain.

54- is raised by a post. 29, the spring 71 is i compY the nuts 72, 73 ressmgz` against 'tlmcup 70 when the ro 64 is moved to euch an extent astocause the, nuts 74 to engage and move the cup 68,` the auxiliary spring 67 will be compressed.

e In' this way one of the posts may be raised and lift that part of the chain with which it is associatedwithout movingother portions of the'chain. The cam 59 remains in contact with the chain at all times. While I prefentn use the flexible spring controlled suspension member shown I do not Vlimit my clalms to such'mechanism as the 'posts may be connected' with the chains in other well liniownA ways.

Certain featuresof the invention 'shown in the accom nying drawings and herein- `-before descri arer claimed in snap lica- ,4 tion of' George John Rackham 8a F erick" ,Iambmled Mtr. 17, 1923, No. c25,-

ni faire amaai ofV and Resum a and sgid, joint application inGreat Bit'ain on Apr. 18, 1922. I claim as my`invent1on:- 'n

1. An' track vehicle comprisihg tractor belts, driving and idle pulleys 1supporting them; a vehicle body, a sub-frame 'connected therewith mounted to rock fore and. aft, and means for suplporting the vehicle body 'com -rising whee s engain the lowerrmis of t e. belts, frames in w ich wheels are mounted, cables connected with tlffhf subject matter of these claims being' the the-sub-frames on which the vehicle body rests, and vertically movable connections -beA tween the frames of the trackengagmg wheels and said cables which also permit the Kframes toewing bodily sidewise or laterally with the tractor belts.

l 2. An endlem track vehicle .comprising a chassis, subframes supported from op osite 'sidesthereof and each mounted -to roc fore and aft about an axis intermediate its front and rear portions, tractor belts on opposite sides of the vehicle, pulleys for the be ried by the front portion ofthe subframcs,` pulleys for the rear portions of the-.belts carried by the chassis, body supportingedevices connected with the 'chassis for vertical" and lateral movement and carried by and ts Car-YM'Y within the ,subframe and which'rock with .lill` Ill) suitl subframes about their pivotal eminem tion with tlie rlnrvi Il. \n miillew` trawl( \el|irle rompiiilig n vlnr-ifi. Ulli-univ mpportrll from opposite sitles tllrleol' `intl mieli moilnteel to I'oelt l'ore :mtl zlt't :ll'oitt :in :l.\i;1 intrrmmliute its: front :1mi rezar poi-lions. trut-toi' lrlt on o1 po-ite .gillen of tile veliirlr. pulleys for the belt` enrriltl l; tlle i'lont portions ol tlie elibfllmen, pulleys for the renr portiom olA the belts carried h r the flmwis. botly supporting wheels engaging tl'w lower rmi:` of the belts. traum-s within tlw -nllr:tlm-s in which the wheel, are monmerl. flexible ezibles ronneetexl with tlie mhh-:unes on which tlie vehicle hotly rest :incl rertiezilly |.io\'a.ble eonneetiom between tlie l'rznmw ot' the laofljfsupporting wlieele :nul mlirl r'zibles wliillt :tlm permit the l`rnme` to swing); sitlewinc or 1ntelzill'v Willi tlie tractor belts.

4. A11 e1itll|n-- track reliitzlr eoinprising :t (lundis. enlifrnmm miepentlwl tlierei'mn.A trm'tor lleltl on opposite sides: of the te bit-le. pulleys for the belts mounted to operate :more the lower rum ot' tlm belts und liml'r supporting devices housed within the liliframlwA nliirli engage the belts and are nioflntetl to more vertimlly nntl also swing laterally within the stili-traumi.

I. An enlllws truck Yeliit-le comprising n rglmesis. subir-antw smpenelefl therefrom, tractor belts on opposite Sitlee. of tlie vellitle, pulleys for tlle belts mounted to operate above tlie lower rum of tl'le belts. :mtl hotly winmx-ting tleviees in the Fnbframes. enel) comprising u wertiealhv movable pont. :i snpport on which the poen-t rests. :t frame sustaining'the post support and which rocks laterally with respect to the post support, :nul wheels Cilrried by* said frame adapted to engage the bell, with wlzirli it is associated.

(l. An entllew track vehicle tfol'lprising n t-lnwsis. soliti-lunes; suspended therefrom. truetor belts on oppohite sides of the vehicle, pulleys` fonltle lie/lts und bothY supporting (lt-rives carried bjr the -enbfimne, each roam prising a Yert`nlly movable post. u lost Anpport on wliieh the post rests, a frame ,sup-

mrtng the post support and which moves laterally and rocks in the Snbframe' und wheels carried by said frame adapted to engiiffe tlie tra'clt.

i. A11 enfileI truck vehicle romprising :L elizisfis. eubtlmnes suspended from opposite sides thereof and each mounted to rock fore und aft about an axis intermediate ite: front und reni' portione, tractor shoes connetetl by universal joint-v adapting the trmfl: to flex laterally :mtl the shoes to rock sitlewise about horizontal fixes, pulleys for tlie belts carrleil by the `nbt'rmnr :intl the chassis :intl hotly elimini-ting rleviees carried by the sul)- fi'zxines interpoeerl between the veliirle body :intl the lower rims of the belts. comprising flexible suspending members connected with the sub-frames on which tliey vehicle body rests. wheels engaging the tracksVfrmneS carried by tlxe Sub-frames in which the wlieelo are mounted :mtl which are mounted to more laterali)Y or Siflewise with the tv aclis, :mtl connection between sai'cl frames and mid flexible suene-riding members.

ln testimoni' whereof. I have hereunto subscribed my nume.

GEORGE JOHN RACKH'AM. 

